Au=gold ppm=parts per million 28.35 grams equal1
Post# of 12259
ppm=parts per million
28.35 grams equal1 oz
Which are units of concentration, more or less a ratio which is unitless. In terms of mg (milligrams) a unit of weight w/c is 28.35 equal to an oz. No definite or exact weight per tonnage in terms of ppm of gold, it varies. I don't know if it helps, I may not be correct in every sense, hard to explain not experience in mining.